S-Adenosyl-L-methionine, known as SAMe, is the main biological donor of methyl groups and it has several important therapeutic applications. As a substance existing in the living body, SAMe has been found to possess various pharmacological actions such as improvement of energy state of ischemic brain, improvement of cerebral energy metabolism and acidosis of the model with recirculated blood flow following ischemia, etc. Variety of other functions such as inhibition of neuronal death following ischemia, improvement of cerebral glucose utility, inhibition of brain edema, improvement of EEG, improvement of evoked potential, amebiorative action on motor function, and therefore reported to be important as a cure for stroke. SAMe as an antioxidant, use for osteoarthritis, liver protection and to control aging in elderly people is also suggested.
SAMe is an important molecule in normal cell function and its survival. SAMe is utilized by three key metabolic pathways: trans-methylation, trans-sulfuration and polyamine synthesis. In transmethylation reactions, the methyl group of SAMe is donated to a large variety of acceptor substrates including DNA, phospholipids and proteins. In trans-sulfuration, the sulfuration of SAMe is converted via a series of enzymic steps to cysteine, a precursor of taurine and glutathione, a major cellular anti-oxidant. Given the importance of SAMe in tissue function, it is not surprising that this molecule is being investigated as a possible therapeutic agent for the treatment of various clinical disorders as mentioned in Int. J. Biochem. Cell Biol. (2000), 32(4), 391-395.